Optical imaging and acoustic imaging (e.g., ultrasound) have each been used as separate modalities for diagnostic imaging. However, optical imaging, and acoustic imaging each have limitations. For example, optical imaging is hampered by relatively poor penetrability and diffusion, while ultrasound imaging is hampered by its spatial and contrast resolution for defining the physiology of images.
New and improved contrast agents and methods of imaging are needed to overcome the limitations in the art. The present invention is directed to these, as well as other, important ends.